To determine our list, we examined the country’s 40 largest metro areas, singling out 20 based on size and geographical representation. Based on expected temperature patterns, historical energy demand and projected heating commodity prices (oil, propane, natural gas and electricity) we calculated how much an average family of four with a 2,100-square-foot house, as defined by the U.S. Department of Energy (DOE), would spend to heat their home. These four heating sources cover just over 98% of household heating needs, and pricing figures were drawn from the DOE’s Energy Information Administration and regional utilities companies. The prices we determined were adjusted for each city’s respective remainder.

Weather played the biggest role in determining the rankings. Demand for heating is higher in Detroit than it is in Phoenix, and for this reason residents of colder climates pay more each year.

To determine demand, we looked at 10 years of National Weather Service data and calculated an index for what are called “heating degree days.” This index, which measures daily temperature and power demand, reflects the spread between outside air temperature and a room temperature of 65 degrees Fahrenheit. This matters because it takes more energy to heat a home on a 10-degree day than on a 30-degree day. Each degree requires more BTUs of heat, which in turn translate to dollars.

Minneapolis, followed by Buffalo, N.Y., were the coldest cities measured. The amount of juice required to keep a home in either city warm far exceeds that which is needed in Boston or New York City.

But you wouldn’t think so looking at each area’s household energy bills.

That’s because the efficiency of a home’s heating system and local energy prices also play a role in determining costs. Homeowners pay more to heat a property in, say, Washington D.C. than in much colder Chicago, because a little more than a third of those living in D.C. rely on electricity to heat their homes, which is more expensive than the natural gas that almost 90% of homeowners in the Windy City use. The same holds true for households in Philadelphia; though temperatures in Denver sink far lower, fuel bills there are less due to a heavier homeowner reliance on electricity.

Fuel Economy

Better yet? Based on a comparison of dollars to energy efficiency, heating oil is a better bet than propane or electricity, but homes that heat using natural gas pay less for the same amount of energy. Cities in the Northeast are far more reliant on heating oil, so not only do residents in New England and the Mid-Atlantic pay more for heat than Midwesterners who largely rely on natural gas, Northeasterners are more vulnerable to the volatility of oil prices.

For example, heating oil prices in Boston have increased 234% in the last 10 years, according to the Energy Information Administration. Natural gas, by contrast, rose just 72% over that same 10-year period.

So why don’t Northeastern cities, which are disproportionately dependent on heating oil, switch to a more affordable fuel source? Because it can cost thousands of dollars to completely reconfigure how a home is heated. Also, the availability and price of natural gas in the Northeast lessens the attractiveness of a switch.

Natural gas is sold in dollars per 1,000 cubic feet. In Boston 1,000 cubic feet of natural gas costs $16.85, compared with $12.38 in Minneapolis. This means that if a Boston household was to switch over completely from heating oil to natural gas for its heating needs, it would save a total of $190 a year, which may not serve as enough of an enticement. If Bostonians could get the Minneapolis rate for natural gas, switching from heating oil would save $515 a year.

Why the disparity? Regional cost differences are governed by the ability of local utility companies to add capacity, meet demand and how the suppliers are regulated and taxed by the states.

The primary unit for how utility supply and capacity functions operate has to do with where demand is focused. Natural gas, like any energy source, becomes marginally less expensive the greater the provider’s capacity. In an ideal, well-regulated sense, capacity is reflective of demand, where higher demand leads to increases in capacity.

However, if you’re waiting for these regional systems to change drastically in the near future, it’s going to be a long winter.